Washington: Heading into the critical US midterm elections, the Democrats have retained their advantage in the battle for the House of Representatives, but Republicans could be buoyed by increasingly positive assessments of the economy, according to a new poll.

The Washington Post-ABC News national poll released on Saturday ahead of the elections slated for November 6, found that registered voters preferred Democratic candidates for the House over Republican candidates by 50 per cent to 43 per cent.

This marked a slight decline from last month, when Democrats led on the generic congressional ballot by 11 points, and a bigger drop from August, when they enjoyed a 14-point advantage.

Democrats also have a 51-to- 44 per cent advantage among likely voters, the poll said.

However, there was no way to translate the national numbers into the district-by-district competition that will ultimately decide who controls the House January 2019.

Democrats need a net gain of 23 seats to capture control of the House.

Meanwhile, President Donald Trump’s approval rating stood at 40 per cent, holding steady from a poll in early October and slightly higher than his 36 per cent rating August.

Those who disapproved accounted for 53 per cent. Among registered voters, Trump’s approval was 44 per cent, with disapproval at 52 per cent, the best margin among this group during his presidency.

Among registered voters, 71 per cent said the economy was good or excellent, up from 60 per cent August. Those who gave the economy positive ratings favoured Republican candidates for the House by 54 to 40 per cent, wider than the 49 to 42 per cent margin in August.

The Washington Post-ABC News poll was conducted October 29 to November 1 among a random national sample of 1,255 adults, with 65 per cent reached on cellphones and 35 per cent on landlines.